Firearms which are capable of full automatic fire are often provided with mechanisms which will permit them to be fired semi-automatically, i.e., only one shot each time a trigger is pulled. This is particularly true with firearms of the type referred to as submachine guns. Moreover, it is generally desirable to provide all firearms with safety means for locking the bolt so that it cannot be released to fire a cartridge in the chamber.
Accordingly, many automatic firearms include selector means which will permit the bolt to be locked in the safe position, and which will provide control over the sear mechanism to permit either full automatic fire or semi-automatic fire. In some instances, this entails a change in trigger position; in other instances, it entails a plurality of separate "switches" or controls. In some firearms, combinations of automatic and semi-automatic bars engaged with the sear are acted upon by the selector mechanism to effect their movement to alternate positions.
It is an object of the present invention to provide a full automatic firearm employing a novel and highly effective trigger, sear and selector mechanism to permit the bolt to be locked in a safe position and to be fired either automatically or semi-automatically.
It is also an object to provide such a firearm wherein the sear is engaged at any one time only with one of a pair of bars which control its movement in response to operation of the trigger.
Another object is to provide such a firearm in which the sear, trigger and selector mechanism is contained in a unitary assembly or a single housing unit readily attached or assembled to the receiver or firearm body.
A further object is to provide such a firearm wherein the parts may be readily and economically fabricated and assembled, and which will exhibit long life and operate in a relatively trouble-free manner.